Studies on sporo-pollen and environment of Late Quaternary on the front edge of Changjiang River Delta

Six palynolo gical assemblages were disting uished through an intensive study on pollen and spores from Cores G2 and XT2 at the frontedge of the Changjiang River Delta.Combined with the data from other cores nearby,six stages about the evolution of vegetation and climate were reconst ructed for the Late Quaternary on this area as follows:mixed sparse forest of conifers and deciduous broad-leave trees,reflecting a cold and dryclimate(Late Pleist ocene);mixed forest of conifers and broad-leave tree-sgrassland,reflecting a temperate and little moist climate(sub-arctic period);mixed forest of conifers and broad-leave trees with a fewevergreen broad-leave trees,reflecting a temperate and slightly dryclimate(the boreal period);evergreen broad-leave forest being mainly composed of Castanopsis and Quercus(evergreen),indicating a hot and moist climate(the Atlantic period);mixed forest of conifers and broad-leave trees,indicated by Quercus,Pinus and Artemisi a as main elementin palynological assem blages,reflecting a warm and little dryclimate(the sub-boreal period);mixed forest of deciduous broad-leaves,evergreen broad-leaves and conifers,Quercus(deciduous,evergreen) and pines,being the main components,reflecting a warm and wet climate(the sub-Atlantic period).These fluctuations coincide with the global climatic changes.The present study provides reliable evidence for biostratig raphy and reconstructions of paleo vegetaton,paleoclimate and paleoenvironment in this area from the Late Quaternary on.